


The Once and Future King

by seperis



Series: The Forever King [1]
Category: Supernatural
Genre: Alternate Universe, Alternate Universe - Canon, M/M
Language: English
Status: Completed
Published: 2017-12-06
Updated: 2017-12-06
Packaged: 2019-02-11 08:29:17
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,996
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12931455
Author URL: https://archiveofourown.org/users/seperis/pseuds/seperis
Summary: This is where forever starts.  Prequel toIn the Hall of the Mountain King.





	The Once and Future King

**Author's Note:**

  * Inspired by [The Game of God](https://archiveofourown.org/works/4592838) by [seperis](https://archiveofourown.org/users/seperis/pseuds/seperis). 



The Pit argues every fucking hour of what passes for a day here and he's getting pretty goddamn tired of it. Especially since it shouldn't be able to argue.

"Not yet," he grates out, ignoring the seared landscape and occasional corrupted soul at the very edge of the Pit's domain, borderlands made of the tortured dead too crazy even for Hell, and he's one of them. He's been running forever, barely ahead of the shits sent to make him kneel for the fucker they call master. Not happening: in a straight fight, he knows right now he could win, but not yet. 

He just wishes he could remember _why_. Why he's running, why he's waiting, why he can't take it all. _Not yet._ There's something else he's got to do first, and it would sure fucking help if he could remember _what_.

The Pit hides him. At least, he thinks it does, grinding its displeasure like the sound of gravel in a blender, but it's doing something, that much is clear. Not that he's risked it anywhere near the rack or where the fucker sits in state since he got away. The Pit's resentment of the fucker's becoming a problem, or would be if he noticed: not too bright. He could-- _not yet_.

It's also not entirely happy about where he's going, but it's not fighting him, either, and that's enough. Enough to keep control of himself: he's got plans, and he can't afford to indulge the rage and betrayal yet for making him wait, but--but that's for after. After, he's gonna teach his recalcitrant buddy a lesson in loyalty, and he'll start by chopping it up and let it spend the next millennia with its pieces buried all over the goddamn Pit in solid--

_Not yet_

\--stop. Plan. First, get it, fix it (at least enough to do its goddamn job), and go from there. The rest--it'll wait. He's patient. Fuck knows he's learned that much.

Coming around the curve of a shaved cliff he doesn't recognize, he stops short, fighting down the desire to rip apart the figure slumped against bare, rust-red rock, stone of the same color spread out beneath him. There's a long moment where he's not sure it noticed him yet, but the dark head turns, exhausted, red-rimmed blue eyes meeting his. There's a dangerous moment where he thinks it just might run--and no way can he control himself if it does that, _fuck_ \--before it slumps back against the cliff.

"Hey, sweetheart," he says pleasantly; this is gonna be done with a pair of pliers, shredding, barely enough to even bury, he can already feel them in his hand and hear it screaming. "Got lost?"

"Alistair," it says, and the Pit surges forward eagerly-- _no, not yet_ \--though he can't remember why he's waiting, he knows he has to. It stares at him for a long time before it frowns, blue eyes widening. "Dean?"

He staggers, grabbing for the cliff: _Dean_. That'd be it. That's what he was waiting for.

Swallowing in a dry mouth, he feel the thrum spread through him and hopes the Pit's hiding him because no way would even that fucker could miss this. Breathing through the shock, he pulls himself together again piece by piece before he loses it again, what they took: _Dean_.

"It worked," he breathes. Dean: that's his name, and that's everything.

"Dean?" it--no, _he_ says again, and Dean takes a deep breath and smiles at him, ignoring the flinch; it's fine, whatever, everything's back on track.

"Yeah," he agrees, looking Cas over: filthy and exhausted and hurt, his first impulse now is to track down everything that fucking _touched_ him and introduce them to the once and future Master of the Pit. It's gonna happen, soon; he'll let Cas watch.

Crossing over to him, Dean drops in a crouch, relieved that Cas doesn't flinch again when he reaches out to tilt his head up, fighting back rage: soon, he tells himself and feels the Pit hum in anticipation. On a guess, whoever's been after him is in a lot worse shape; he'll have to ask about that.

"What have you been doing to yourself?" he asks, turning Cas's head carefully, reading his condition by touch and liking nothing he's picking up. Running on empty and even that's almost out: nowhere in Hell to hide and no one to protect him, with a price on his head the highest ever offered. He remembers laughing on the rack when he heard about it, choking on his own shredded lungs and unable to stop: best joke he ever heard, catch _Cas_? Tell the mountain to bow, shithead: tell the moon to fall and the sun to rise and end the universe with a big bang all your own, your chances are better doing all three. The only time anyone catches Cas is when he wants to be caught.

"Dean?" Cas breathes in disbelief, then shakes his head, belatedly trying to pull away. Dean tightens his grip but doesn't make the mistake of turning this into a competition. Cas may escape with a broken jaw, but he _will_ escape, and he can't risk that, not now that he's here. "No. You're not--"

"I am," he says, testing it; pretty much, give or take, but that shit he didn't need anyway, not here. "It worked, Cas. I told you it would."

Cas shuts his eyes. "I'm sorry--"

"I'm not." Though he wouldn't say it was fun; he got someone who couldn't break a goddamn serial killer and it got assigned _him_? Bullshit: they're gonna learn about standards and soon. He'll get Cas to teach 'em. "Cas, look at me."

"Stop it!"

"You're being stupid," Dean says fondly; Cas doesn't get it, that's fine, he'll learn, they got time now. All of it, come to think. "Can't run forever, you know that. You came here, didn't you?"

He really wishes Cas would look at him. "I didn't know where I was going."

"Funny," Dean says, mouth quirking. "All of Hell, and you come to the one place in the Pit I'm hiding after I get off the rack." Cas's mouth tightens, and letting him go, Dean shifts to sit beside him. "It's hiding me, anyway. What a coincidence, huh?"

Drawing up his legs, Cas drops his head onto his knees, and Dean waits, easy; he planned for this, after all. Moving slowly--he doesn't pretend Cas can't do some serious damage to him even now--he reaches to tug up Cas's sleeve, hissing at the open sores, rings of bruises, scrapes marring all that skin; he's taking payment for all of it in full, soon. Cas doesn't lift his head but doesn't fight him either, shivering when Dean traces the binding cut that survived even death; his own shivers in sympathy, relieved not to be stretched so far anymore. That means something, and Cas knows it as well as he does. 

"I'm tired." Dean holds himself perfectly still. "I felt you break. I wasn't--I couldn't get to you in time. Again."

Which might explain the incompetence of his particular torturer; everyone else was guarding the Pit and never coming back. Not an excuse, but he gives them credit for knowing how dangerous Cas was, at least. "How many did you take out?"

The blue eyes flicker up, and Dean catches the cold blue rage, unhealed, unhealing: he likes it. Can use it, too. "Not enough."

"It's okay--"

"How?" Cas looks at him, eyes wet, tears drawing pale lines down filthy his cheeks, and Dean reaches out without thinking, wiping them away with his thumb. "I don't understand, how can you be so much like Dean---"

"I _am_ Dean," he interrupts; okay, he got this. "How long has it been?"

"One hundred and eight years, three months, one week, five days, sixteen hours, twenty-seven minutes, eighteen seconds." Cas's voice breaks. "Five years, one month, six days, twenty-eight hours, two minutes and forty-one seconds since you broke."

Felt like longer, but when you have to do half the work for your goddamn torturer, time gets weird. "It was supposed to be this way," he says, hushing Cas when he starts to protest. "It had to be, Cas."

"It's over," Cas says. "We failed."

Distantly, Dean feels his recruits circling closer and sends a warn-off with prejudice; from the agonized response, he thinks they got the 'not the fucking time'. "No we haven't," he says. "We haven't even started. We're gonna win, Cas. Here."

Cas stiffens, but the instant rejection is absent; he's tired, yeah, and probably stopped thinking around the time Dean broke on the rack. Which is pretty much what he hoped for; he couldn't plan this part, but sometimes, things just work out.

"Hey." Carefully, he draws a finger down Cas's arm, following the open wounds (can't wait to find out who did that and where to find them). "Gonna fix this up?"

Cas snorts softly. "You know I can't."

He can, he just doesn't know it yet; Dean's got so much to teach him. "I can." Cas stiffens belatedly and Dean adds another check to his side--their side--of the board. He was never gonna do this without Cas, that was a given, whatever happened; he told Cas they were in this together and that's never changed. "Come on, let me help. You wanna run, fine but at least let me fix you up so you can."

Cas turns his head against his knee, and the incredulous look almost makes Dean laugh; fuck, he missed him. "You'll let me leave?"

"I'll never let you go," he answers honestly. "But it'll give you a fighting chance, at least."

The cracked lips part in a soft laugh: check. "You sound like him--"

"I am him," Dean interrupts. "You can feel it, Cas, come on." 

Watching Cas carefully, he calls in the knife, blade sharp enough to cut air, and lets go of Cas's arm to draw a short cut near the elbow of his left forearm. Cas's expression is a few novels, all contradictory--revulsion, rejection, horror, disgust, terror, and the only one that counts-- _hunger_. Check.

"No," Cas says, but the blue eyes never leave that cut, blood welling suggestively. There's power in blood given freely, but here, at least, there's just as much in accepting it; he wonders if Cas realizes that. "I won't--"

"You want to run, you're gonna have to." Cas flickers a look at him, and he knows he won. "It's _me_ , Cas. Come on, it doesn't have to be this hard."

He can make it easy, though; shifting closer, he holds out his arm and watches Cas bend closer as if drawn, waiting, and finally, the sweep of Cas's tongue against his skin before his lips part around the cut and he starts to suck.

He expected everything but the sheer _rush_ ; catching his breath, Dean just manages not to tumble over like an idiot, and he realizes he's got a hand in Cas's hair, holding him there with no memory of actually moving.

Fuck: here he thought Ruby was just getting off fucking up Sam. He just _didn't know_.

"That's it," he breathes as Cas fastens a dirty hand around his wrist before doing what Dean almost did; he's ready for it, though, bracing himself when Cas collapses against him. It takes a long moment to remember what else he's supposed to be doing, but check it out; he doesn't need to do anything but let it happen. Like it's supposed to: of course it is, what was he thinking, this is him and Cas, this is _them_. "There we go. Take all you want."

If he had the Pit behind him, this might be faster, but Alistair couldn't do this any more than Lucifer could or anyone else; the only one who can corrupt Castiel is Dean. That's why he needed his name first; names are powerful, wrong one and you just might become them. He may have to use Alistair's name, but he'll keep his own when he does. 

Already, he can feel it working into Cas; all those subtle cracks everyone has, widening them slowly and carefully, but those wouldn't be enough, not with Cas. This is about _him_ ; him, working his way into Cas, lighting up all the places in Cas that are his, have been since this started. Infinite mind of an angel: might scare anyone else, but not Dean, never has, and he needs to know if he's right about how this is gonna work. No margin for error: this is Cas, and he's gotta get everything right the first try.

Then Cas jerks back-- _tries_ to jerk back, but he doesn't get any farther than leaning against Dean's chest, lips smeared red. That wasn't enough--not nearly enough--but Dean seals the cut for now; might be better this way, let it work in him, offer more. Cas won't ask this time, or the next, but he will after that, and then he won't need to ask ever again. He'll figure it out.

"I'm so tired," Cas whispers, and Dean gathers him closer, resting his chin in the dark hair and feeling Cas's body shake. "When you broke, I thought--nothing I did mattered."

Dean nods, but he's got to know. "What'd you do with the fucker's minions? None ever came back."

"I put them to good use," Cas says in a different voice, and Dean pulls back to look down and sees a faint smile. "It took time to decide on the shape, however. Their screaming was distracting, so I stopped it."

Now that he's thinking about it, it's quiet over here. The rest of Hell is a cacophony of noise, but here.... "Where are they?"

"Beneath and behind us." Cas looks up, and bewildered, Dean follows his gaze to the cliff, then the stone floor. "Ah, I forgot." Raising a hand, he snaps his fingers, and Dean gets a secondhand rush from Cas using his blood-borne power; they're doing that again like, _yesterday_. "What do you think?"

Like turning up the volume on the radio, the screaming starts, and it takes Dean a second to work out where it's coming from: _everywhere_. The cliff behind them, the rock beneath them--Dean presses a hand against the ground and the screaming intensifies; it's beautiful. He can feel the Pit hum approval--not a surprise, this is fucking _art_ \--and from the way Cas stills, he feels it, too: perfect. He's gonna be incredible when Dean's done with him; Cas'll be the best he's ever made, he know it.

"Amazing." He kisses Cas and tastes blood; with it comes the memories, a breathtaking flow of images of five years when nothing mattered: only Cas would create a monument to it. Five years.... He jerks back, startled by the edge of something else. "You were waiting for me. Here." 

He waits for Cas to deny it, but he just looks back. "My death was not my own," he answers. "Like my life, it belongs to you."

A monument to his once and future death at Dean's hand. Christ. "That was never gonna happen," he says fiercely; how could Cas think he'd _ever_ \--

"Maybe I hoped it would." Before Dean feel anything but horror, he shrugs. "At least, I thought I did. As it turns out, that's not what I wanted after all." 

Dean realizes he's clutching Cas hard enough to break bone and with an effort loosens his grip. It never occurred to him that Cas might not--that he.... "Do you even know what you want?"

"The only thing I ever wanted." The blue eyes meeting his. "You."

Dean breathes out, relief so strong it feels like pain. "You have me, Cas. Always."

There's a long moment of silence. "Convince me." 

"What?"

"Convince me." Turning his face against Dean's chest, he makes a broken sound, and it's all Dean can do not to claim the Pit now so he can take care of everything that made Cas sound like that. "I don't care what it is, just convince me to do it."

That, he can do. "I have a plan."

Shifting them back so he can lean against the cliff, Dean gathers him closer and tells him everything.

* * *

Just before they start, Cas says, "Don't stop until it's done."

Dean nods. It's not like he doesn't know the risks here; he just doesn't care. Cas is worth anything. "I know."

"If you can't break me--"

"I will," Dean says; he won't believe anything else. "Don't worry about it."

"--I don't leave this room," he continues like Dean didn't say anything. "Not ever."

"I can do this," he says, checking the restraints again; he designed this room a thousand times in his mind just for Cas, and it's everything he imagined. Smooth volcanic rock that reflects as clearly as a mirror, so he can see Cas from any angle, and just as importantly, Cas can always see _him_. He shaped the rack to Cas alone, everything in it everything that Dean knows about him, and Cas made the restraints himself, designed to bind an angel. Not really required here, though; nothing and no one can hold Cas when he doesn't want to be. It's gonna take both of them to do this; he doesn't doubt Cas at all and he can't, _won't_ doubt himself. They can do this.

"One more thing," Cas says, and Dean looks up and drowns in blue eyes. "Promise me I won't hate you."

"You won't," he says, picking up the first knife. The only way to break Cas is to make him want it, and the only person that can make him want it is Dean. He can do this. Pressing the tip into the hollow of his throat, he kisses him one more time. They have forever now. "You'll love me. I promise."

**Works inspired by this one:**

  * [Cover for 'The Once and Future King' (in the style of Bratfarrar)](https://archiveofourown.org/works/12933612) by [ab-insula-Avalonia (AurumCalendula)](https://archiveofourown.org/users/AurumCalendula/pseuds/ab-insula-Avalonia)




End file.
